Tag: bio-chemistry

Questions Related to bio-chemistry

Facilitated diffusion can be differentiated from active transport except

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Energy does not required

  2. Show saturation effect

  3. Accumulation of molecule

  4. (1) and (3) both

Show answer
Correct Option: D
Explanation:

In facilitated diffusion ,special proteins help move substances across membranes without expenditure of  ATP energy. While in case of Active transport it uses energy to pump molecules against a concentration gradient .

In both case , transportation rate reaches a maximum when all of the protein transporters are being used (saturation).
So the correct option is 'One and three both' .

The process of facilitated diffusion is different from active transport due to

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Involvement of membrane protein

  2. Its response to protein inhibitors

  3. Being a downhill process

  4. Saturation of transport

Show answer
Correct Option: A

Facilitated diffusion can not cause net transport of molecules from a low to a high concentration because -

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. This would require output of energy

  2. This would require Input of energy

  3. Both (1) and (2)

  4. None of these

Show answer
Correct Option: A

The physical process involved in the release of molecular oxygen from leaves is

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Diffusion

  2. Transpiration

  3. Osmosis

  4. Capillarity

Show answer
Correct Option: A
Explanation:

Diffusion is a slow process and is not dependent on a living system. Diffusion is very important to plants since it the only means for gaseous movement within the plant body. Intake of carbon dioxide and release of oxygen through stomata occurs through the process of diffusion. Diffusion rates are affected by the gradient of concentration, the permeability of the membrane separating them, temperature and pressure.

................ is the change in the value of a quantity with change in another variable.

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Variant

  2. Valency

  3. Gradient

  4. Density

Show answer
Correct Option: C
Explanation:

Gradient is the change in the value of a quantity with change in another variable. Example time, solute concentration, pressure potential, solute potential, etc.

Density is the degree of compactness of a substance.
Valency is the number of electrons an atom can donate, share or accept to achieve a stable octet.
Variant is a quantity that changes its value.
So the correct answer is 'Gradient'.

Which of the following prevents an ion to cross the plasma membrane via simple diffusion?

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Ions are too large.

  2. Ions carry a charge.

  3. Ions are hydrophobic.

  4. Ions do not produce a concentration difference.

  5. Ions cannot interact with membrane-bound proteins.

Show answer
Correct Option: B
Explanation:

Ions are small atoms or molecules carrying an electric charge. The core of plasma membrane is composed of nonpolar hydrophobic lipid tails and prevent simple diffusion of these charged particles. Thus, the correct answer is B. 

If the amount of an ion absorbed by a root hair cell at $0^{0}C$ is 5 gm and at $20^{0}C$ is 20 gm. The amount of this ion absorbed actively should be

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. 25 gm

  2. 20 gm

  3. 15 gm

  4. 5 gm

Show answer
Correct Option: C
Explanation:

At 0 degree Celsius the respiration rate will be zero. At 20 degree Celsius only the respiration process will take place. Hence, the 5 gm initially absorbed is due to physical diffusion of mineral ions from a region of high to low concentration. Later on, respiration occurs, then extra 15 grams are actively absorbed.

Which of these is/are not a property of facilitated transport?
(a) Requires special membrane proteins
(b) Highly selective
(c) Uphill transport
(d) Requires ATP energy

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. a and b only

  2. c and d only

  3. a and c only

  4. b and c only

  5. b and d only

Show answer
Correct Option: B
Explanation:
  • Facilitated transport or diffusion or passive-mediated transport can be defined as the process of spontaneous passive transport of molecules or ions across a cell membrane through the specific transmembrane integral proteins.
  • It does not require the ATP molecules and is the diffusion is downhill.
  • So, the correct answer is 'c and d only'.

Which does not pertain to facilitated transport?

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. Uphill transport

  2. High selectively

  3. Transport saturation

  4. Requirement of special membrane proteins

Show answer
Correct Option: A
Explanation:

Facilitated transport is the movement of molecules across a membrane through special transport proteins.

The movement is in accordance with the concentration gradient and hence a downhill transport.
Transport proteins provide high selectivity and transport only certain molecules.
Example: Ion channels, aquaporins, etc.
So the correct answer is 'Uphill transport'.

Choose the correct statement regarding facilitated diffusion:

bio-chemistry plant physiology active transport and passive transport types of plant transport atp

  1. It is fast process

  2. Expenditure of ATP occurs

  3. Break down the concentration gradients

  4. Does not requires special membrane proteins

Show answer
Correct Option: A